As
@Hunterman said, and depending on how often you're in 4WD I'd toss in the front diff too. But I am very OCD about that stuff, so I am on the overkill side of things. Being in AZ, the heat is the enemy on the diff/transfer case/tranny, so I just change them all at the same. I probably should do the front since it has less fluid but since I don't use FWD as much as I would if I were back home in MT, I got a little lazy.
My change intervals:
Oil Change - 5,000 miles - I run the SPE MS pan with 18 quarts so I should go a tad longer but 5K is easy to do
Fuel Filters - 25,000 miles - I run the SPE MS filter setup with the Ultra Efficiency CAT Secondary
Front Diff - 75,000 miles - I run the PPE diff cover
Rear Diff - 50,000 miles - I run the PPE diff cover
Transfer Case - 50,000 miles
Transmission - 50,000 miles - I run the SPE MS pan
CCV - 5000 miles - I run the SPE MS Internal CC and Recirculate setup, so I clean the screen every oil change
Air Filter - 25,000 miles - I have the Banks with the sock, so I clean the dry filter at 25,000 and replace at 50,000